This invention relates to cathodic protection of tubular goods transporting hot fluids. More particularly, the output efficiency of a sacrificial aluminum or zinc anode is increased by thermally insulating the anode from the pipe on which it is placed.
The use of sacrificial anodes made of aluminum, zinc, or their alloys on the outer surface of tubular members is well known. In many cases, the anode is placed on or around a tubular pipeline member that is either buried in the earth and that is used to conduct hot fluids, that is, fluids with a temperature above 100.degree. F. Heat inside the tubular member is transferred to the anode and the anode output efficiency decreases. For example, at 180.degree. F., the useful output drops to about 50%.